1. Field of the Invention
The present invention relates to a printing system which is configured to be capable of performing square back processing, a job processing method, a storage medium, a program product and a printing apparatus.
2. Description of the Related Art
Recently, there has been proposed a POD (Print On Demand) printing system using an electrophotographic printing apparatus or an inkjet printing apparatus (see Japanese Patent Laid-Open Publications No. 2004-310746 and No. 2004-310747). The POD printing system of this type is advantageous in that block copy preparation and other complicated operations required by an offset plate making printer can be dispensed with.
On the other hand, in the POD market, there can be demands for creating various forms of printouts. For example, there can be a demand for creating a printout subjected to saddle-stitching bookbinding (hereinafter also referred to “saddle-stitched brochure”) having a special form obtained e.g. by performing a squaring process for making square the back of a saddle-stitched brochure (such that a square back is formed). To perform a squaring process such that the back of a saddle-stitched brochure is flattened (i.e. roundness of the back is suppressed) is referred to as square back (or square hold) processing. There has been proposed a technique for performing the square back processing by a special post-processing apparatus (see Japanese Patent Laid-Open Publication No. 2006-159894).
However, the above-mentioned post-processing apparatus capable of performing the square back processing is configured to be usable as an offline finisher provided independently of a printing apparatus. For this reason, an operator (or a user) is required to carry out work for taking out a printout after execution of printing by the printing apparatus, and manually setting the printout in the post-processing apparatus.
In view of this situation, it can be expected that the POD market or the like will demand a printing system in which a post-processing apparatus capable of creating a saddle-stitched brochure subjected to square back processing can be made use of as an inline finisher connectable to a printing apparatus, in the future. Further, it can be expected that there will be a demand for a printing system which is capable of carrying out an entire process from print processing executed by a printing apparatus to creation of a saddle-stitched brochure subjected to square back processing, in the future.
In a case where a printing system is configured to be capable of meeting the above-mentioned demands, it is preferable to prevent occurrence of a trouble due to the fact that the system is configured to be capable of performing the process from print processing to square back processing.
However, the present situation is not such that the above-mentioned possible problem of occurrence of the trouble is tackled to provide a countermeasure for making such a printing system commercially available/practical, and hence, no research has been made on a mechanism for preventing occurrence of troubles that can occur in the following situations:
Let it be assumed, for example, that the printing system has a trimmer unit capable of trimming a saddle-stitched brochure delivered from the printing apparatus, at a fore edge of the brochure, which is an opposite end from the back of the same. The trimmer unit trims the saddle-stitched brochure by a predetermined trimming amount specified by a distance from the fore edge of the brochure. Assume, on the other hand, a case where the trimmer unit of the printing system is capable of trimming both a saddle-stitched brochure in a job not requiring square back processing and a saddle-stitched brochure in a job requiring square back processing. In this case, when the trimmer unit trims the saddle-stitched brochure in the job requiring square back processing, an event can occur in which one or more outer sheets (which can include not only a cover sheet disposed on the outermost side of the printout (i.e. a sheet bundle formed by a plurality of sheets and folded in half by saddle-stitch processing), but also one or more outer sheets of the main portion of the printout) of the brochure are not trimmed, but only one or more inner sheets (i.e. the main portion) of the same are trimmed, which makes the creation of the brochure wasteful.
Further, assume a case where the printing system tentatively performs printing using ordinary sheets and saddle stitching of printed sheets to check the finished state of a saddle-stitched brochure, and then in actual printing, performs reprinting using thick sheets to thereby create the saddle-stitched brochure. Further, let be assumed that a saddle-stitch job originally configured to be one not requiring square back processing can be changed to one requiring the square back processing. When the printing system is thus configured, the above-mentioned event can occur in which the substance (one or more inner sheets) of the saddle-stitched brochure is trimmed, but one or more outer sheets including a cover sheet are not.
Furthermore, although there occurs no problem with printing positions in processing without square back processing, the saddle-stitched brochure trimmed as above after being subjected to processing with square back processing can suffer from the problem of a shift in image position being caused between inner sheets and outer sheets of the brochure.
As described above, when the printing system is constructed to be capable of performing square back processing, there is a possibility of a new trouble of inadvertently creating a saddle-stitched brochure defective in the appearance of a trimmed edge and/or print appearance, which is unexpected by an operator.